Collecting devices for collecting bodily waste, ostomy appliances, wound or fistulae drainage bandages or devices for collecting urine are usually in the form of a receptacle, e.g. a bag, pouch or tube for receiving the waste, connected to an adhesive wafer that can be attached to the skin of the patient. The wafer is typically in the form of a backing layer coated on the skin-facing surface with an adhesive layer and the wafer may further be provided with an aperture for accommodating the body opening. The size and shape of said aperture can often be adapted individually to fit the anatomy of the patient.
One of the crucial parts of such devices is the adhesive wafer. The wafer should be able to fit leak proof around the body opening, have good adherence to the skin without unintended detachment from the skin, but at the same time be easy to remove again without damaging the skin. Furthermore, the wafer should be able to follow the movements of the body and be comfortable to wear.
When designing a skin adhesive one of the major issues is to keep the skin relatively dry underneath the adhesive to prevent maceration. Maceration occurs when the skin is unable to get rid of moisture from transpiration and outlet from a body opening. This may result in degradation of the skin's barrier function as well as bad adhesion of the device to the skin.
Usually, skin adhesive keeps the skin dry by absorbing moisture. Absorbing particles or hydrocolloids (HC) are mixed into an adhesive matrix in order to absorb moisture from the skin and thereby the skin is kept relatively dry. This technique is well known in the art and forms the basis for most ostomy adhesives that are commercially available see, e.g. U.S. Pat. No. 4,192,785.
To improve the ability of the adhesive wafer to resist leakage, some wafers include a secondary adhesive surrounding a first adhesive center. The first adhesive is positioned adjacent to the output source and the secondary adhesive supplies additional leakage resistance. U.S. Pat. No. 4,775,374 describes an adhesive construction, wherein both the first and the secondary adhesive are hydrocolloid (HC) based. In this adhesive construction, both the first and the second adhesive are sensitive to the output that they are supposed to resist. Additionally, they will both swell when getting in contact with the output. Thus, the failure mechanism is the same for both adhesives and the added protection is limited. Other products, such as the Microskin adhesive with washer sold by Cymed, include a first and a second adhesive where the second outer adhesive is an acrylic adhesive. Acrylic adhesives are known to cause allergic reactions on skin and are therefore problematic. Furthermore, known secondary adhesives strip or otherwise damage the skin upon removal, which can be painful and discomforting to the user.
It has now surprisingly been found that by combining a standard HC adhesive with a polyethylene copolymer based adhesive system, the problem with allergic reactions can be avoided. Furthermore, the standard HC adhesive and the polyethylene copolymer adhesive system are very different in adhesion properties. Thus, the two adhesives characteristics can complement each other to achieve better adhesion than one of the adhesives could achieve alone. Finally, the polyethylene copolymer based adhesive system is non-damaging and less painful to remove, providing a more comfortable secondary adhesive.